feat(cluster): PG Logical Replication + VIP/Keepalived + config_hash sync (v1.2.1–1.2.2)

- PG Logical Replication: edgeguard_shared PUBLICATION auf Primary,
  edgeguard_sub SUBSCRIPTION auf Secondary. Nur geteilte Config-Tabellen
  werden repliziert; node-eigene Daten (network_interfaces, ip_addresses,
  static_routes, cluster_settings, dns_settings, ntp_settings) bleiben
  lokal — OPNsense-Muster.
- cluster-init-replication: Erstellt PUBLICATION, Rolle + pg_hba-Einträge
  (logical + replication), WAL-Level auf logical.
- cluster-setup-standby: Erstellt SUBSCRIPTION (copy_data=true), pollt
  pg_subscription_rel bis alle Tabellen sync = 'r', rendert dann Configs.
- promote: manueller Failover via pg_promote() + touch recovery.signal.
- VIP/Keepalived: cluster_settings-Tabelle (vip_address, vip_interface,
  vrrp_router_id), /cluster/vip-settings API, Keepalived-Config-Generator
  mit VRRP + check_script + notify-Skripten in /usr/lib/edgeguard/scripts/.
- config_hash sync: Secondary pusht alle 5 Min seinen Hash via mTLS an
  Primary (PushSelfToPrimary). Heartbeat schreibt nur LOCAL, daher ohne
  aktiven Push wäre Primary-Sicht des Secondary-Hash stale gewesen.
- runSecondaryConfigRender: Goroutine auf Secondary rendert HAProxy+nftables
  neu wenn config_hash sich ändert (Logical-Replication-Nachzügler).
- confighash: node-spezifische Tabellen aus hashSpec entfernt.
- postinst: Keepalived-Skripte installieren, sudoers für keepalived.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

deploy/keepalived/keepalived.conf.tpl

@@ -0,0 +1,40 @@
+global_defs {
+    router_id {{ .RouterID }}
+    script_user root
+    enable_script_security
+    vrrp_garp_interval 0
+    vrrp_gna_interval 0
+}
+
+vrrp_script chk_edgeguard {
+    script "/usr/lib/edgeguard/keepalived-check.sh"
+    interval 2
+    weight -50
+    fall 3
+    rise 2
+}
+
+vrrp_instance VI_1 {
+    state {{ .State }}
+    interface {{ .Interface }}
+    virtual_router_id {{ .RouterID }}
+    priority {{ .Priority }}
+    advert_int 1
+{{ if .SrcIP }}    unicast_src_ip {{ .SrcIP }}
+    unicast_peer {
+        {{ .PeerIP }}
+    }
+{{ end }}    authentication {
+        auth_type PASS
+        auth_pass {{ .AuthPass }}
+    }
+    virtual_ipaddress {
+        {{ .VIP }}
+    }
+    track_script {
+        chk_edgeguard
+    }
+    notify_master  "/usr/lib/edgeguard/keepalived-master.sh"
+    notify_backup  "/usr/lib/edgeguard/keepalived-backup.sh"
+    notify_fault   "/usr/lib/edgeguard/keepalived-backup.sh"
+}